Rubber process and product



RUBBER PROCESS AND PRODUCT .Filed Feb. 15, 1957 ILS/@hmz Ifefl Ol Patented May 9 19379 UNITED 4 STA-rss PATENrffoFF-ICE j alum v lminnen. rnocEss'ANn raonUc'r v Thoma. Lewis shepherd, Landon, England Application reuma" 15.1931. serial Nai'zsbss* In Great. Britain February 19, 1986 f8 Claims. '(01.18-54) This invention relates to elastic rubber threads or yarns and their use in the manufacture of textile fabric, knitted or .lacework and the like or parts thereof.

5 When rubber threads are led intoa loom or knitting machine so as to be formed into a fabric it is very often diil'cult to control the rubber threads because of the extensive and variable stretch that they possess and the resultof this i0 is that the fabric when completed has a 'non-unl-A form surfaceappearance or thatshirring or other defects are present in'the nished material.

The object of vthe invention is to overcome this disadvantage and for this purpose to provide an improved rubber thread which is relatively inextensible during theweavlng or knitting into a fabric, and which can be treated when in'1 the fabric so-as to render it relatively extensible.

The invention will now be described by way 'of 30 example. it being understood that the nature of the invention will be specied in the accompanying-claims.

In carrying the invention into eii'ect in one form by way of example a rubber thread is wound g5 in an ordinary'doubling, twisting or winding machine with a strip of gelatine in the form of a thread or filament with about six turns per inch.

The gelatine is then caused to adhere by passing the yarn through steam and subsequently so 'Ihe accompanying drawing shows an enlarged view of a rubber thread with a gelatine thread wound thereon. The thread is -then incorporated Y as desired in the fabric, giving a-ilat fabric which is then vboiled and washed until the gelatine is gg removed. i

The rubber regain all their extensibility, and can contract if they are incorporated in the fabric in a stretched condition.

Ihe winding referred to in the above example- Instead of being in the form of a thread or lila-- I0 ment. the gelatine may be a band, and its effect in reducing extensibility will be increased as the width of the band is increased; it will be found advisable. however, not -to have the stripof too great width, since the flexibility of'the thread Il may be undesirably reduced. For normal thicknesses of rubber` thread, i. e. .02" diameter, the band might be from .01" to .08" in width, when the number of turns per inch is 10. It is possible to use such a width and Vpitch in conjunction that the gelatine entirely covers the rubber g thread, the coilsoverlapping one another, and in a modification of the invention the step of treating with steam may be omitted in such a case.

The treatment with steam may result in the fusion oi' adjacent bands of gelatine and fusion 1. may also be arranged to take place by the treatment with steam of a thread so closely covered with a helical winding of gelatine thread that adjacent coils are in contact. The result is a covered or coatedrubber thread with considerable uniformity in the covering orcoating and a closely predetermined thickness of such covering or coating.-y

The thread to which the gelatine is applied may contain gelatine or like extensibility reduc- $0 ing agent. The thread may therefore itself become to afgreater or less extent tacky during the Y steaming, and it may alone, or in addition, be so rendered tacky before winding.

The winding may .take place before the thread 85 is dried after its formation.

The thread to whichthe lgelatine is applied may be progressively stretched to render it temporarily non-elastic or may be coated with an adhesive for the same purpose. In the case of a 80 coating it mayif suitable be rendered tacky alone. or in addition, before winding.

Instead of gelatine, related bodies such as the glues may be used.l These. or the gelatine. may

for example after winding be treated or may be 86 compounded with hardening agents, such as eluminium sulphate, formaldehyde and tannic acid. to mahe the thread more resistant to moisture,

with softeners s uch as glycerine to make it more pliable and with known diluents such as sucrose. 40

it less susceptible to humidity. Besides glue and 46 gelatine, agar-agar and water soluble cellulose ethers may be used, and other suitable substances.

. such as resins, for example, vinyl resin, and rubber derivatives, for example, rubber hydrochlo-` ride. lInstead of steam4 or in conjunction there- 50 with, suitable processes, depending upon what is necessary to render the substance-of the winding tacky, sticky, or adherent, may be used for ensuring that the gelatine or the like adheres rmiy to the rubber thread; for example, bensol or solvent naphtha for the treatment of vinyl resin and rubber hydrochloride.

'Ihe invention is not limited to rubber" in the narrow sense, but includes threads also of balata, gutta-percha, synthetic rubber and other extensible and elastic materials. In the same way the wood latex includes aqueous dispersions of such materials.

I claim: v

l. A method of rendering,rubber thread relatively inextensible consisting in winding a soluble inextensible thread about the rubber thread, causing the said soluble thread to adhere to the rubber thread by treating the same with a solvent for the soluble thread, and drying the rubber thread thus treated. Y

2. A method as claimed in claim 1 in which the soluble thread winding consists ot gelatine and the solvent therefor is water.

3. A method `of rendering rubber thread relan tively inextensible consisting in winding a soluble :lnextensible thread about a rubber thread in which an extensibility-reducing agent has been incorporated during manufacture, causing the soluble thread to adhere to the rubber thread by treating the same with a solvent for the soluble thread, and drying the rubber thread.

A method of rendering rubber thread relatively inextensible consisting in applying to rubber thread in a freshly formed and still moist state, a winding of a Water soluble thread to cause adhesion of the solubley thread to the rubber thread, and subjecting a thread to a drying operation.

5. A method of rendering rubber thread relatively inextensible consisting in applying thereto a coating of a water soluble extensibility-reducing agent and applying to the said coating while in a tacky condition a .winding of soluble inextensible thread, and subjecting the rubber thread to a drying operation.

6. A relatively inextensible rubber thread composed of rubber upon which is wound and adhered a thread oi gelatine.

7. A method of rendering rubber thread inextensible consisting in winding thereon an inextensible solublev at thread so that the convolutions are in contact with one another, treating the rubber thread thus wound with a solvent for the at thread so vthat the convolutions adhere to one another and to the rubber thread, and drying the latter.

8. A method as claimed in claim 7 in which the fiat thread is gelatine and the solvent therefor is water. Y

'THOMAS LEWIS SHEPHERD. 

